Can Word open a .odt file?

I totally agree. If you like ODF, then by all means use it. Since ODF is native to LibreOffice, and LibreOffice also supports OOXML, then you get the best of both worlds.

If you need all the features of Microsoft Word, then your best bet is to use Microsoft Word. LibreOffice simply doesn't have all of Word's features.

Neither office suite takes up much RAM or disc space by today's standards. As Phillip says, use both suites as you decide is appropriate.

Why all the Arguments?

Do as I do. I have:

LibreOffice

OpenOffice

NeoOffice

Office2011

I keep them all up to date.

BTW the latest version of 4.5.2 LibreOffice supports direct saving .docx format in the SaveAs for the Write section:

I'm sure the Excel equivalent and Power Point Equivalent  are similar.

Of One Caution the people now handling the down load are allowing a Virus type Application to be installed if you accidentally check a box of forget to uncheck it. I managed to remove it. Before it got too serious.

The true will you free.

http://en.wikipedia.org/wiki/OpenDocument

The standard was developed by a technical committee in the Organization for the Advancement of Structured Information Standards (OASIS) consortium.[3] It was based on the Sun Microsystems specification for OpenOffice.org XML, the default format for OpenOffice.org, which had been specifically intended "to provide an open standard for office documents."[4]

Initial release 1 May 2005; 9 years ago

OpenDocument 1.3 (a.k.a. "ODF-Next") As of January, 2014, the current state of a possible future version of OpenDocument specification is a working draft (a preliminary unapproved sketch, outline, or version of the specification). The OASIS Advanced Document Collaboration subcommittee (created in December, 2010) is working on an update of OpenDocument change-tracking that will not only enhance the existing change-tracking feature set, but also lay the foundation for the standardization of real-time collaboration by making change tracking compatible with real-time collaboration.[27][28][29]

http://en.wikipedia.org/wiki/Office\_Open\_XML

Office Open XML (also informally known as OOXML or OpenXML) is a zipped, XML-based file format developed by Microsoft[2] for representing spreadsheets, charts, presentations and word processing documents. The format was initially standardised by Ecma (as ECMA-376) and, in later versions, by ISO and IEC (as ISO/IEC 29500).

Initial release 7 December 2006; 7 years ago

The ISO standardization of Office Open XML was controversial and embittered,[18] with much discussion both about the specification and about the standardization process.[19] According to InfoWorld:

OOXML was opposed by many on grounds it was unneeded, as software makers could use OpenDocument Format (ODF), a less complicated office software format that was already an international standard.[18]

— InfoWorld

The same InfoWorld article reported that IBM (which supports the ODF format) threatened to leave standards bodies that it said allow dominant corporations like Microsoft to wield undue influence. The article further says that Microsoft was accused of co-opting the standardization process by leaning on countries to ensure that it got enough votes at the ISO for Office Open XML to pass; although it does not specify exactly who accused Microsoft.[18]

Not helpful. ODF is widely supported by various competitors to Microsoft. That is probably why he says it is outdated, which is plain wrong. Microsoft Office might not support it, but others do and the UK government just accepted it as the official document format used for exchange with the authorities along with PDF. So ODF is actually a sound format to use. If you need to exchange formal documents, use PDF instead.